The present invention, in some embodiments thereof, relates to methods of generating cells from mesenchymal stem cells that secrete neurotrophic factors and, methods of selecting same.
Amyotrophic lateral sclerosis (ALS) is one of the most common neurodegenerative diseases in adults. It is a fatal progressive neurodegenerative disease characterized by motor-neuron cell death in the brain and spinal cord accompanied by rapid loss of muscle function and eventual complete paralysis.
Current experimental ALS drugs are developed on the basis of putative pathophysiologic mechanisms, such as anti-glutamatergic agents, drugs targeting protein misfolding and accumulation, antioxidant therapy, immunomodulatory agents, and stem cells.
Of the current investigational therapies, stem cell transplantation may have the most potential. Apart from the replacement of lost or damaged motor neurons, stem cell implantation therapy may benefit ALS patients by an independent effect of cytoprotection. Further, there is the potential for stem cells to differentiate into supportive interstitial cells including astrocytes and microglia which can potentially produce neurotrophic factors as well as enzymatic and paracrine mediators which antagonize neurotoxicity. Further experimental data have shown that non-neuronal cell replacement can be a strategic therapy in promoting motor neuron survival and improved neuromuscular function (Corti S et al. 2010).
The use of stem cells as a cellular source in cell replacement therapy for additional neurodegenerative diseases including Parkinson's disease and multiple sclerosis has also been suggested.
Neurotrophic factors (NTF) are small, naturally occurring polypeptides that support the development and survival of neurons, and therefore have been considered in the past few years as candidates for therapy options for different neurodegenerative diseases including ALS. Studies in ALS animal models have shown a delay in disease onset and/or progression after administration of various neurotrophic factors.
However, clinical trials of systematic or intrathecal administration of recombinant growth factors to ALS patients have not been effective, probably due in part to their short half-life, low concentrations at target sites, and high incidence of side effects.
Several studies have shown that mesenchymal stem cells (MSCs) following exposure to different factors in vitro, change their phenotype and demonstrate neuronal and glial markers [Kopen, G. C., et al., Proc Natl Acad USA. 96(19):10711-6, 1999; Sanchez-Ramos, et al. Exp Neurol. 164(2):247-56. 2000; Woodbury, D., J Neurosci Res. 61(4):364-70, 2000; Woodbury, D., et al., J Neurosci Res. 69(6):908-17, 2002; Black, I. B., Woodbury, D. Blood Cells Mol Dis. 27(3):632-6, 2001; Kohyama, J., et al. Differentiation. 68(4-5):235-44, 2001; Levy, Y. S. J Mol Neurosci. 21(2):121-32, 2003, Blondheim N. R., Stem Cells & Dev. 15:141-164, 2006]
WO2006/134602 and WO2009/144718 teaches differentiation protocols for the generation of neurotrophic factor secreting cells from mesenchymal stem cells.
WO2007/066338 teaches differentiation protocols for the generation of oligodendrocyte-like cells from mesenchymal stem cells.
WO2004/046348 teaches differentiation protocols for the generation of neuronal-like cells from mesenchymal stem cells.
Abbaszadeh et al [Iranian Biomedical Journal 17 (2): 62-70 (April 2013)] teaches a two step differentiation protocol for the generation of oligodendrocytes from MSCs where one of the media comprises PDGF, heregulin, bFGF and triiodothyronine.